This invention concerns compositions comprising oleum Melaleuca and methods for using the compositions to treat lesions.
Lameness in animals can lead to death or a decrease in the commercial value of the animal. There are multiple causes for the condition ranging from genetic defects to bacterial and viral infections. For example, fibroma (corns) is a genetic condition found in cattle which causes a hard, fibrous lump to form between the claws of the foot. The corn makes the hoof more susceptible to subsequent bacterial and viral infections. These infections occur at various locations in and around the hooves of the cattle. Greenough et al., Lameness in Cattle 3rd, (1996).
In addition to the general lesions caused by infection, a disease of unknown etiology has been spreading throughout the western United States. This disease is digital dermatitis (DD). DD is characterized by painful lesions, which often are surrounded by a ridge of hyperkeratotic (thickened) skin with finger like projections. For this reason, the disease is commonly referred to as hairy wart.
DD is contagious and has spread rapidly throughout cattle herds in the United States. A survey of cattle owners showed that 17.2% of cows and 6-8% of bred heifers in the 12 months before Feb. 20, 1996, showed signs of the disease. USDA Papillomatous Digital Dermatitis on U.S. Dairy Operations (1997). In addition to causing lameness in cattle, DD also causes decreased milk production and sometimes death. Dairy farmers report as much as 50% less milk being produced per cow. Linda Leake, Farm Journal, Inc., (1998).
Currently, cattle are being treated for lameness using antibiotics, topically applied caustic compounds and/or foot baths containing formaldehyde or tetracycline. While these treatments are useful, they also introduce unwanted contaminants into the food chain. The use of tetracycline on dairy cattle, for example, can lead to the production of contaminated milk having little-to-no commercial value. The FDA has restricted the use of several antibiotics, including streptomycin, chloramphenicol, tetracycline and penicillin. Nevertheless, in order to achieve rapid healing and to avoid loss of income, prohibited antibiotics may be misused.
Oil extracted from the Australian tea tree (oleum Melaleuca alternifolia) has been used by the aboriginal people since before the first european settlers arrived. One of the first published reports concerning the oil identified its germicidal qualities as being 11-13 times more effective than phenol. Dr. E. M. Humphrey, MJA; 1:417-418 (1930).
In 1978 a list was compiled of 48 different compounds found in oleum Melaleuca alternifolia. Greg Swords and G. L. K. Hunter, J. of Agricultural Food Chemistry, 26:3, pp. 734-737 (1978). See, Table 1 below. Of these compounds, terpinen-4-ol is considered to be the most active ingredient, but experiments using terpinen-4-ol alone have shown that it is not nearly as effective as the complete oil. Purity and effectiveness of the extracted oil is determined by the terpinen-4-ol content and cineole content. Typically, high quality oil includes up to 60% terpinen-4-ol and less than 10% cineole.
Oleum Melaleuca alternifolia has been combined with aloe and used to suppress flea infestation in domestic animals. See, Fitzjarrall""s U.S. patent No. 5,449,517. Oleum Melaleuca alternifolia also has been combined with butylated hydroxy toluene to suppress herpes lesions, menthol to relax muscles, gum to treat burns, and benzaldehyde to repel stinging insects. See, Mankovitz""s U.S. Pat. No. 5,385,733, VanderSloot""s U.S. Pat. No. 5,096,709, DiPippo""s U.S. Pat. No. 5,009,890, and Sackin""s U.S. Pat. No. 5,738,863, respectively.
Additional research has shown that oleum Melaleuca alternifolia inhibits fungal and bacterial growth. A minimum inhibitory concentration (MIC) for fungal growth was determined using agar dilution techniques, and a MIC for bacteria determined using disc diffusion. These MICs were from about 0.4% to about 0.5% for fungi and from about 0.2% to about 0.5% for Staphylococcus aureus. Nenoff et al., Skin Pharmacol., 9:6, pp. 388-944 (1996), and Carson et al., J. Antimicrob. Chemother., 35:3, pp. 421-424 (1995), respectively.
The present invention provides compositions containing oleum Melaleuca, and methods for using such compositions. Particular compositions, referred to herein as MSC compositions, comprise oleum Melaleuca alternifolia, a water-soluble form of oleum Melaleuca alternifolia and a carrier. In a working embodiment, the carrier was glycerin and the water-soluble form of oleum Melaleuca alternifolia was Sol-U-Mel(copyright).
The concentrations of each of the individual components can vary. Using 100% oleum Melaleuca alternifolia to treat livestock lesions is not preferred because it requires multiple applications per day to effectively treat the lesions. The concentration of the oleum Melaleuca alternifolia and the water-soluble form of oleum Melaleuca alternifolia in the MSC composition generally range from about 2% by weight to about 50% by weight relative to the total weight of the MSC composition (unless stated otherwise, all percent values stated herein are relative to the total weight of the particular composition being discussed). The remainder of the MSC composition typically is glycerin, but such compositions also can include additional materials useful for providing therapeutic compositions. In one working embodiment, the composition comprised about 13.8% by weight oleum Melaleuca alternifolia, about 12.7% by weight Sol-U-Mel(copyright) and about 73.5% by weight glycerin.
The invention also provides a method for treating animals, particularly for treating lesions, using embodiments of the MSC composition. xe2x80x9cAnimalxe2x80x9d as used herein shall mean all mammals, but generally not humans, and typically refers to livestock such as cattle. The method comprises providing an MSC composition, and contacting the lesion with a therapeutically effective amount of the composition for a therapeutically effective period of time.
The MSC composition also can be used in combination with a bandage, such as the working embodiment illustrated in FIG. 1. This bandage comprised an absorptive material having a resilient backing. The absorptive material maintains the composition in contact with the animal, such as over and about lesions, for a therapeutically effective period of time. The resilient material helps flow the MSC composition on, into and about lesions.
The present invention also provides compositions that are particularly useful for treating DD. These compositions comprise oleum Melaleuca alternifolia, a water-soluble form of oleum Melaleuca alternifolia, at least one additional antimicrobial agent, typically a carrier, and perhaps other materials that are useful for forming compositions for treating DD. In one working embodiment, the carrier was glycerin, the water-soluble form of oleum Melaleuca alternifolia was Sol-U-Mel(copyright) and the antimicrobial agent was selected from the group consisting of Brilliant Green, Gentian Violet, Proflavine hemisulfate, and mixtures thereof.
The concentrations of each of the individual components in the DD composition can vary. DD compositions typically comprise at least about 0.2% to about 50% by weight oleum Melaleuca alternifolia, and from about 0.2% to about 50% by weight water-soluble form of oleum Melaleuca alternifolia. The concentrations of Brilliant Green and Gentian Violet generally vary from about 0.05% to about 5% by weight, and preferably from about 0.2% to about 0.5% by weight. The concentration of Proflavine hemisulfate typically ranges from about 0.01% by weight to about 5% by weight, and preferably from about 0.1% to about 0.5% by weight. The total amount of Brilliant Green, Gentian Violet and Proflavine hemisulfate typically is less than about 1% by weight. The remainder of the composition comprises a carrier, particularly glycerin, and perhaps other materials useful for forming compositions for treating DD. In one working embodiment, the DD composition comprised about: 73% by weight glycerin; 13.8% by weight oleum Melaleuca alternifolia; 12.7% by weight Sol-U-Mel(copyright); 0.2% by weight Gentian Violet; 0.2% by weight Brilliant Green; and 0.1% by weight Proflavine hemisulfate.
The invention also provides a method for treating DD. This method comprises contacting lesions with therapeutically effective amounts of embodiments of the DD composition for a therapeutically effective period of time. The composition can be used in combination with a bandage as described above for use in combination with the MSC composition.